Turmeric has been in use in Asian cookery for thousands of years. Powder ground from the dried root is an ingredient in curry. Because turmeric is one of the cheaper spices and makes a vivid splash of color, it gets heaped into low-market curry blends as fill. Not such a bad idea.

Turmeric holds a high place in Ayurvedic medicine as a "cleanser of the body" and today science is finding a growing list of diseased conditions which turmeric's active ingredient heals.

Ground from the root of a plant (Curcuma longa L.) of the ginger family, found wild in the Himalayas and grown across South Asia, turmeric powder is surprisingly bland, not hot, tangy or peppery. The powder tastes a little sour. The first time I put some on my tongue I suspected my jar, purchased from a supermarket, was stale. Turmeric is pungent, bitter and astringent, not sweet like ginger. Fresh root, which goes well in snacks and main meals, as yet may be hard to find outside of stores in Asian neighborhoods. Turmeric capsules are sold through a number of suppliers.

But why make this spice part of the diet? Let's not romanticize South Asian nutrition today. Although India is doing relatively well, 47% of children there are underweight (Nutrition for Health Development, chart). South Asia's nutritional crises and disparities are harsh. Centuries of charcoal fires for home and industry have contributed to deforestation. Clean water, a cure for malaria, vaccinations and reproductive health care, not more spices, are what most of the citizens of those lands need to improve their health. Yet the very survival of peoples in South Asia must at times have depended on informed use of a wide array of stored dried plants including turmeric root.

A Little Dab

Most North Americans consume only miniscule traces of turmeric, say, by way of mustard lavished on meats of iffy provenance. Bright yellow mustards like French's "classic American" contain, labels say, "no more than 2 per cent" turmeric, paprika and other spices (as if more would adulterate the product). Mustard itself is medicinal. But that gaudy, store-bought, hot-dog-stand glow comes from curcumin, the intense yellow pigment in turmeric. And curcumin protects the stomach against tainted foods. According to University of Chicago scientists, curcumin inhibits a cancer-provoking bacteria (H. pylor) associated with gastric and colon cancer (Magad GB, Anticancer Res. 2002 Nov-Dec;22(6C):4179-81).

On the margins, so some biologists say, eco-diversity sprouts. Today curcumin is on a margin between ancient food customs and cutting-edge medicine. In suburban cuisine it can brighten and glorify nutritious foods (cauliflower, white fish ). At ballpark, beach and food mall a dab of "hidden" curcumin helps carnivore bellies lower risks from gorging on over-handled broiled oddments. In Asia the root and powder are used in cooking, home remedies and medicine: to gild and help preserve festive dishes and in drinks, ointments and poultices to treat sore throat, sprains, inflammation and wounds. In the lab, scientists are dosing rats with curcumin to measure its effects on cancer.

Prostate Cancer Patients Go For the Gold

Turmeric lore in recent decades drifted outwards from Asian diaspora communities in European cities like Leicester, UK. Local researchers and cancer patients listened up. Clusters of men on Internet prostate cancer support groups (notably Don Cooley's lists) began seriously experimenting with turmeric to cope with a troublesome side-effect of androgen-suppression therapy, gynecomastia (sore swollen breasts). Most men who take antiandrogen drugs like Flutamide (Eulexin) or Casodex experience this breast swelling, which can be painful. Gynecomastia can occur also with use of finasteride (Proscar), prescribed for BPH (benign growth of the prostate) and now under discussion as a chemo-preventive for prostate cancer. Before starting Casodex some patients opt to receive a brief course of radiation to the breasts. Others have tried low-dose tamoxifen, which raises levels of circulating estradiol. Then there are the turmeric warriors, who report that dietary intake of turmeric (in salads, soups and sandwiches made with fresh root) and use of curcumin paste externally brings some relief.

Still more intriguingly, University of Leicester began investigating dietary agents including curcumin, genistein, and the vitamin A analogue 13-cis retinoic acid for tumor-suppressing properties (Br J Clin Pharmacol 1998 Jan;45(1):1-12; update Toxicol Lett 2000 Mar 15;112-113:499-505). They observed that curcumin slows the rate at which hormone-responsive prostate cancer cells become resistant to hormonal therapy.

Antioxidant, anti-inflammatory and anti-carcinogenic properties of turmeric and curcumin are undergoing intense research. Tests in Germany, reported July 2003, found that "All fractions of the turmeric extract preparation exhibited pronounced antioxidant activity...." Turmeric extract tested more potent than garlic, devil's claw, and salmon oil [ J Pharm Pharmacol. 2003 Jul;55(7):981-6]. Does this mean, the more the better?

Not necessarily. Some studies find no ill effects from large doses but others (listed in references below) disagree. Of note, a recent study of curcumin to prevent cataracts found, unexpectedly, that in rats low doses did lower cataract rates but heavy doses raised the rate of cataracts (Molecular Vision 2003; 9:223-230, full text free online). Another study found that rats fed large amounts of turmeric for 14 days developed enlarged, damaged livers.

Several studies indicate that curcumin slows the development and growth of a number of types of cancer cells. In Japan this year researchers defined curcumin as a broad-spectrum anti-cancer agent. Its induction of "detoxifying enzymes," the researchers say, indicate its " potential value ... as a protective agent against chemical carcinogenesis and other forms of electrophilic toxicity. The significance of these results can be implicated in relation to cancer chemopreventive effects of curcumin against the induction of tumours in various target organs"
(Iqbal M, et al. Pharmacol Toxicol. 2003 Jan;92(1):33-8).

Since India won a claim against two US scientists who shamelessly patented turmeric (see sidebar), the tide of interest may naturally be driven in part by Asian pride in phytomedicinal heritage. But as scientists at M. D. Anderson, Texas, wrote in January 2003: "Extensive research over the last 50 years has indicated [curcumin] can both prevent and treat cancer. The anticancer potential of curcumin stems from its ability to suppress proliferation of a wide variety of tumor cells, down-regulate transcription factors NF-kappa B, AP-1 and Egr-1; down-regulate the expression of COX2, LOX, NOS, MMP-9, uPA, TNF, chemokines, cell surface adhesion molecules and cyclin D1; down-regulate growth factor receptors (such as EGFR and HER2); and inhibit the activity of c-Jun N-terminal kinase, protein tyrosine kinases and protein serine/threonine kinases." In their latest of a series of reports the M. D. Anderson say: "Curcumin can suppress tumor initiation, promotion and metastasis. Pharmacologically, curcumin has been found to be safe. Human clinical trials indicated no dose-limiting toxicity when administered at doses up to 10 g/day. All of these studies suggest that curcumin has enormous potential in the prevention and therapy of cancer." [Aggarwal, BB et al, Anticancer Res. 2003 Jan-Feb;23(1A):363-98].

To sum up -- regular healthy folks may benefit from adding turmeric to the spice rack and using it more liberally on adult and childrens' foods. Kids love bright colors. And turmeric is an ideal brightener for rice and for steamed or gently fried tofu.

For cancer patients, until curcumin has been shown in well-designed, well-conducted human clinical trials to have measurable effects on existing disease, it remains just another interesting home remedy with a lot of promise. Research at Memorial Sloan- Kettering a few years back indicates that it makes sense to drink green tea along with a meal spiced with turmeric for double-boosted anti-cancer protective effects: "EGCG and curcumin, were noted to
inhibit growth by different mechanisms, a factor which may account for their
demonstrable interactive synergistic effect." But we're still waiting for the cure. For new developments, M. D. Anderson looks like one place to watch.

If you are taking medications or undergoing radiotherapy or chemotherapy to treat cancer, be extremely cautious about possible interactions and negative effects of turmeric/curcumin on treatment and on your liver and other organs. Ask your radiologist, oncologist and oncology nurse.

References

1. On tumor cells in a lab dish, curcumin prevents or slows prostate and lung cancer. But dietary consumption of turmeric, researchers report, so far shows no effect on those organs and failed to inhibit tobacco-induced tumors (Cancer Lett 1999 Apr 1;137(2):123-30).

3.Tufts researchers say "a mixture of curcumin and isoflavonoids is the most potent inhibitor against the
growth of human breast tumor cells. These data suggest that combinations of
natural plant compounds may have preventive and therapeutic applications
against the growth of breast tumors induced by environmental estrogens" (Environ Health Perspect 1998 Dec;106(12):807-12)

7. Curcumin may or may not protect against cellular damage from radiation, perhaps depending on dose. It appears to protect against damage to certain organs brought about by some chemotherapy agents. In hamsters it protects the kidneys from Adriamycin (Br J Pharmacol 2000 Jan;129(2):231-4). If you are taking radiation or chemotherapy, it is very important to discuss your diet and use of any antioxidants with your oncologist.

8. Typical dietary amounts of turmeric have an antioxidant effect that protects rats from cataracts (Toxicol Lett 2000 Jun 5;115(3):195-204). But in one study rats heavily dosed developed more cataract signs.